US Bridges

Nd Highway 8 over Flat Creek

Fair

Adams County, North Dakota · South Jct. US 12 · Structure no. 0008003883

Built
1959
66 years old
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
90 ft
3 main spans
Daily traffic
1,730
2019 count
Owner
State
State Highway Agency

About this bridge

Nd Highway 8 over Flat Creek is a concrete continuous slab carrying Nd Highway 8 over Flat Creek in Adams County, North Dakota. It was built in 1959, so it is 66 years old, older than the North Dakota average of 48.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 1,730 vehicles a day, roughly 6% of them trucks, projected to reach 750 by 2039. The structure is 90 ft (27.4 m) long and 36 ft wide. If it were closed, the detour would be 39.8 mi (64 km).

Location

Open in Google Maps
CarriesNd Highway 8
CrossesFlat Creek
LocationSouth Jct. US 12
RouteState Highway 8
CountyAdams County
StateNorth Dakota
Coordinates45.99933, -102.64485
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.2 US tons
Inventory rating31.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length90 ft (27.4 m)
Longest span30 ft (9.1 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,730 (2019)
Projected traffic750 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed39.8 mi (64 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nd Highway 8 over Flat Creek built?

It was built in 1959, making it 66 years old in 2025.

What condition is Nd Highway 8 over Flat Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2024.

How much traffic does Nd Highway 8 over Flat Creek carry?

About 1,730 vehicles per day (2019 count), of which roughly 6% are trucks.

How long is Nd Highway 8 over Flat Creek?

The structure is 90 ft (27.4 m) long with a longest span of 30 ft (9.1 m) and a deck 36 ft wide.

Who owns Nd Highway 8 over Flat Creek?

It is owned by the State Highway Agency.